D & C Yellow Nos. 10 and 11: delayed contact hypersensitivity in the guinea pig.

D & C Yellow No. 11 was found to be a skin sensitizer in guinea pigs at an elicitation concentration of 10.0% in ethanol but not at 1.0 and 3.0%. Sensitization was induced with a 50% suspension in ethanol. D & C Yellow No. 10, the disodium salt of the mono- and disulfonic acids of D & C Yellow No. 11, was not a skin sensitizer nor was it capable of eliciting a response in the D & C Yellow No. 11-sensitized guinea pigs even at a challenge concentration of 10%. Two commercial products, a soap containing 0.015% D & C Yellow No. 11 and a shampoo containing 0.002% D & C Yellow No. 10 did not elicit a reaction in the D & C Yellow No. 11-sensitized guinea pigs.